The SpitV had 6 months before the F4 came out, and then had to fight against the F4 for a year. That was a quote from another thread (might be the spit thread). The F-0 through the F-4 were built and developed inside of 6 months, and didn't last very long before the F-4 came out. I don't think that's a long enough timespan to allow for a variant.
The E-7, however, was faster than the E-4, had a better engine, better high alt performance with an improved WEP system, and served for years. Not necessarily against the SpitV, as the 109F was being developed to counter the spitV. However the E-7 fought all other types of aircraft, including hurris and other lend-lease aircraft sent to Russia (think FinRus setups), if you want an early setup you really can't put the E4 in because often the setup is unbalanced, so they F4 is put in to make it more playable. With the E-7 you'd not need to compromise.
With Tunisia or Med setups you'd have the E-7, which flew against hurris, spits, and other aircraft in the desert setting. 109E4 vs hurriMk1 is one thing, but E4 vs HurrMk2 is another. The E-7 would be better able to handle the intermediate aircraft, including FAA wildcats and the like.
Hey I'm not 100% attached to the E7, don't think I've gone totally nuts. If there are no 109 additions I'll be fine with that. I'm just sharing why I think it'd be more useful than an F-2